He went on: "I know that the Arsenal fans will be disappointed with my exit from the club, but I'm here to face an incredible challenge, the challenge of my life.

"I'm going to try very hard to make this team more competitive and stronger. If I can add even a little to make this team stronger, it would be a dream come true. I will work very hard to be able to earn my place here."

Appearing alongside Fabregas at the news conference was Barcelona's deputy chairman Josep Maria Bartomeu, who said the fee was €29 million ($42m) with other performance related bonuses.

"Arsenal will receive a bonus of five million euros, two [million] for each league win and one for the Champions League.

"His buyout clause will be 200 million euros [$289m] if we win the league twice and the Champions League once in the next five seasons," he added.

Fabregas, who could make his Barca debut in the second-leg of the Spanish Super Cup against Real Madrid on Wednesday, also reserved special praise for Arsenal manager Arsene Wenger and said the Frenchman had been like a father to him.

"The relationship [with Wenger] is fantastic, I spoke to him on Friday to say goodbye to him. I got very emotional because he has been like a father figure to me.

"I couldn't talk at one stage and I had to send him a message afterwards to says what he has done for me. If it wasn't for him I wouldn't be here today living my dream."

Wenger used his own press conference at Arsenal's training ground to say that Fabregas' desire to leave the Emirates Stadium had nothing to do with money.

"Yes, we lost a world class player and we are sad about it," the 61-year-old said. "We did try to keep him but in the end we have to respect the desire of the player as well.

"It is very difficult to get the best out of a player, he has to be completely committed to where he is. If you understand one thing, it is that Cesc didn't go for financial reasons. He wanted to go back to his home city."

The former Monaco coach could also lose French international Samir Nasri, who has been linked with a move to Manchester City.

Nasri, 24, used his official Twitter blog to hit back at Arsenal fans who he said had been signing offensive songs about him during Saturday's 0-0 draw with Newcastle United.

"I heard what the fans were singing about me on Saturday and it is really disrespectful because I'm still a Arsenal player," read the former Marseille player's Tweet.

Arsenal face Serie A Udinese in the first leg of the Champions League qualifying tie on Tuesday, before entertaining Liverpool in the Premier League on Saturday.